EU Emissions Trading System — The Definitive Reference

Executive Summary

The EU Emissions Trading System is the binding cap-and-trade scheme established by Directive 2003/87/EC and substantially overhauled by Directive (EU) 2023/959 of 10 May 2023, which transposed the “Fit for 55” package’s headline carbon-pricing reforms into directly applicable EU law. It is the world’s largest carbon market by traded value and the operative mechanism through which the EU translates its overarching 2030 climate target (55% net emissions reduction versus 1990) into a tonne-by-tonne, installation-by-installation, financially-enforced compliance obligation on the entities responsible for roughly 35% of EU greenhouse-gas emissions.

The system does six things uniquely. It puts an absolute, declining cap on covered emissions — the cap reduces by 4.3% per year from 2024 to 2027 and 4.4% per year from 2028 to 2030, with two one-off “rebasing” reductions of 90 million allowances in 2024 and 27 million in 2026 on top of the linear reduction. It auctions the bulk of allowances via EEX (the common auction platform for 25 Member States, Iceland, Liechtenstein, and Norway) and other national platforms, with the auction clearing price providing the primary public price signal that ripples through energy markets, industrial capex decisions, and corporate financial planning. It allocates a declining share of allowances for free to manufacturing sectors deemed at risk of carbon leakage — declining from 97.5% free allocation in 2026 to zero by 2034 for CBAM-covered sectors, in lockstep with the phase-in of the Carbon Border Adjustment Mechanism. It runs a Market Stability Reserve that absorbs surplus allowances when the Total Number of Allowances in Circulation exceeds 833 million, providing a structural mechanism to absorb temporary supply gluts and tighten the cap further than the Linear Reduction Factor alone would deliver. It is being extended to a second, parallel system — ETS2, covering road-transport fuels, buildings heating fuels, and small industry — with compliance now postponed to 2028 by March 2026 EU Council and Parliament decision. And it interlocks with CBAM to extend the carbon price to non-EU imports of carbon-intensive goods, preventing the carbon-leakage failure mode that an unilateral price ceiling on EU-domestic production would otherwise create.

What the EU ETS Is — and What It Is Not

The EU ETS is a market-based environmental policy instrument grounded in Article 192(1) of the Treaty on the Functioning of the European Union. The legal architecture is a directive (Directive 2003/87/EC, as amended), which means Member States transpose the substantive provisions into national law and designate national competent authorities for permit issuance, MRV enforcement, and registry administration; the underlying market infrastructure (auctioning, the EUTL, the Market Stability Reserve, the Innovation Fund, the Modernisation Fund) is operated at EU level by the European Commission and ECHA-adjacent institutions.

The ETS is not a tax, a fund, a target, a directive on energy efficiency, a renewable-energy mandate, or a national policy instrument. It is a cap-and-trade scheme: a binding absolute upper limit on emissions, combined with a tradable property right (the EUA) that operators must surrender against verified emissions. The price of the EUA is not set by the Commission or by any other regulator — it is discovered by the market, subject to the supply curve defined by the cap and the demand curve defined by covered emissions. The Auction Reserve Price floor that exists in some national carbon-pricing schemes (notably the UK ETS) does not exist in the EU ETS; the only EU-level price-management tool is the Market Stability Reserve, which is quantity-based, not price-based.

The ETS is also not, by itself, a corporate climate-disclosure regime. Verified emissions reports submitted under the EU ETS feed the corporate Scope 1 inventory but do not constitute a Scope 1 inventory in the GHG Protocol sense, do not satisfy ESRS E1-6 disclosure, do not satisfy SBTi target-tracking, and do not satisfy CDP Climate Change reporting. Each of those downstream frameworks consumes ETS-verified emissions data but applies its own boundary, materiality, methodology, and GWP-basis rules. The relationship is one of nested data flows, not of equivalence.

“Covered emissions” under the ETS means the greenhouse-gas emissions from the Annex I activities at installations holding a greenhouse-gas-emissions permit, plus aviation emissions from intra-EEA flights and from departing flights to Switzerland and the UK, plus maritime emissions from voyages between EU ports and within EU ports plus 50% of emissions from voyages between an EU port and a non-EU port. The covered gases are CO₂ across all sectors, N₂O from nitric and adipic acid production and from glyoxal/glyoxylic acid production, and PFCs from primary aluminium production. Methane and N₂O from maritime are added to the EU ETS scope from 2026.

Why the EU ETS Exists

The EU ETS exists because the Kyoto Protocol of 1997 introduced the conceptual framework for international flexibility mechanisms — emissions trading, joint implementation, and the Clean Development Mechanism — as a cost-minimising approach to greenhouse-gas-emission reductions under a binding international target. The European Communities, having ratified the Kyoto Protocol with a collective burden-sharing commitment of an 8% reduction in 1990 emissions across the 2008–2012 first commitment period, needed a domestic policy instrument that could deliver that commitment at the lowest aggregate cost. Cap-and-trade was the answer: by setting a binding cap and letting the market price marginal abatement, the EU could in principle deliver any target at the lowest aggregate cost the market could discover.

The first three trading phases progressively refined the mechanism. Phase 1 (2005–2007) was the learning phase — national allocation plans, free allocation through grandfathering, and a structural oversupply that drove the Phase 1 EUA price to effectively zero by mid-2007. Phase 2 (2008–2012) coincided with the Kyoto first commitment period, tightened the cap, and added auctioning as an allocation method. Phase 3 (2013–2020) introduced the EU-wide single cap (replacing the national caps of Phases 1–2), introduced the Linear Reduction Factor (1.74% per year), shifted the default allocation method from free allocation to auctioning, and introduced the harmonised product benchmarks that determine free-allocation entitlements for installations remaining eligible for free allowances.

Phase 4 (2021–2030) was first designed against the 40% reduction target under the 2014 EU 2030 climate framework, with a Linear Reduction Factor of 2.2%. The arrival of the European Green Deal in 2019 and the 2021 European Climate Law (Regulation (EU) 2021/1119), which raised the 2030 economy-wide target from 40% to at least 55% net reduction versus 1990, triggered the substantial 2023 reform of the ETS Directive. The Fit for 55 package, of which Directive (EU) 2023/959 is the central instrument, raised the ETS sectoral target to 62% reduction by 2030 compared to 2005, increased the Linear Reduction Factor, added two one-off rebasings, extended the system to maritime, established ETS2 for road transport and buildings fuels, introduced CBAM as the carbon-leakage backstop replacing free allocation, and tightened the Market Stability Reserve mechanics.

The driver behind each successive expansion is the same: the marginal abatement cost in EU ETS sectors is now low enough that further reductions inside the existing cap are deliverable, while emissions in road transport, buildings, and small industry have stayed structurally higher per unit of economic output and require their own price signal to drive substitution toward electrified transport, low-carbon heating, and low-carbon process technology. ETS2 is the EU’s answer to that problem — a parallel, upstream system that prices the carbon content of road fuels and heating fuels at the fuel-supplier level, propagating through the economy to end-consumer prices and creating the substitution incentive at the point of consumption.

Publication History

The EU ETS has a clear four-phase lineage with significant amendment activity in each transition. Key milestones below are reconciled to the Official Journal record.

Governance: Who Owns and Enforces the System

The EU ETS operates on a multi-level governance model. Strategic ownership sits with the European Commission’s Directorate-General for Climate Action (DG CLIMA), which is responsible for the directive’s policy direction, for proposing amending directives and delegated and implementing acts, for setting the annual EU-wide quantity of allowances through Commission Decisions, and for the annual Carbon Market Report that documents the operation of the system to the European Parliament and Council.

The European Commission also operates the central registry infrastructure — the EU Transaction Log (EUTL) — which records every allowance transaction across all national registries, every surrender against verified emissions, every transfer between operator-holding accounts, and every cancellation. The EUTL is the single source of truth for EUA holdings and movements across the EU 27 plus Iceland, Liechtenstein, Norway, and Northern Ireland electricity generators.

Auctioning is operated by the European Energy Exchange (EEX) under a contract with the Commission as the common auction platform for the 25 Member States plus Iceland, Liechtenstein, and Norway that have opted into the common platform. Germany and Poland operate national auction platforms (EEX serves as Germany’s national platform under separate arrangement; Poland uses EEX for its national auctions following the 2016 transition). The auction calendar, reserve price (a soft technical reserve based on the secondary market price prior to auction, not a hard price floor), and bidding methodology are governed by the Auctioning Regulation (Commission Regulation (EU) No 1031/2010 as substantially amended).

National competent authorities — designated by each Member State — are responsible for the on-the-ground compliance regime: issuing greenhouse-gas-emissions permits to operators, approving installation Monitoring Plans, receiving verified annual emissions reports, enforcing surrender obligations, administering free-allocation calculations under the Free Allocation Regulation, operating national registries (as sub-systems of the EUTL), and imposing penalties for infringements. The competent-authority designations and enforcement intensity vary substantially across Member States; multi-site operators typically interact with multiple competent authorities across their EU footprint.

Verifiers are private accredited bodies operating under Implementing Regulation (EU) 2018/2067 on the verification of operators’ annual emissions reports, supervised by Member State national accreditation bodies operating under Regulation (EC) No 765/2008 and reference standard ISO/IEC 17029 / ISO 14065. A verifier’s accreditation is sector-specific (combustion, mineral oil refining, iron and steel, cement, aluminium, chemicals, glass, ceramics, paper and pulp, etc.) and substance-specific (some verifiers are not accredited for the perfluorinated emissions covered in primary aluminium, for example).

The European Environment Agency (EEA) compiles the annual EU-level emissions inventory that feeds the Commission’s compliance reporting under the Paris Agreement and the EU’s Nationally Determined Contribution. ESMA — the European Securities and Markets Authority — is the financial-markets regulator with oversight of EUA trading on regulated markets and OTC, publishing the annual ESMA Carbon Markets Report that documents trading activity, position concentration, and the financial-stability dimensions of the carbon market.

Scope — Sectors, Installations, and Activities

The ETS scope runs along three dimensions: which activities, which installations within those activities, and which gases. Each is defined precisely in Annex I of the directive.

Activities in scope (Annex I)

Annex I lists the activities that bring an installation into the system. The principal categories:

• Combustion of fuels in installations with a total rated thermal input exceeding 20 MW (except installations for the incineration of hazardous or municipal waste).
• Refining of mineral oil.
• Production of coke.
• Metal ore (including sulphide ore) roasting or sintering, including pelletisation.
• Production of pig iron or steel (primary or secondary fusion) including continuous casting, with a capacity exceeding 2.5 tonnes per hour.
• Production of ferrous metals (including ferro-alloys) where combustion units with a total rated thermal input exceeding 20 MW are operated.
• Primary aluminium production — includes PFC emissions, not just CO₂.
• Secondary aluminium production where combustion units with a total rated thermal input exceeding 20 MW are operated.
• Production of cement clinker in rotary kilns with a production capacity exceeding 500 tonnes per day or in other kilns with a production capacity exceeding 50 tonnes per day.
• Production of lime, or calcination of dolomite or magnesite in rotary kilns or in other furnaces with a production capacity exceeding 50 tonnes per day.
• Manufacture of glass including glass fibre with a melting capacity exceeding 20 tonnes per day.
• Manufacture of ceramic products by firing, in particular roofing tiles, bricks, refractory bricks, tiles, stoneware or porcelain, with a production capacity exceeding 75 tonnes per day.
• Manufacture of mineral wool insulation material using glass, rock, or slag with a melting capacity exceeding 20 tonnes per day.
• Drying or calcination of gypsum or production of plaster boards and other gypsum products, where combustion units with a total rated thermal input exceeding 20 MW are operated.
• Production of pulp from timber or other fibrous materials.
• Production of paper or cardboard with a production capacity exceeding 20 tonnes per day.
• Production of carbon black, soot, or activated carbon involving the carbonisation of organic substances such as oils, tars, cracker and distillation residues, where combustion units with a total rated thermal input exceeding 20 MW are operated.
• Production of nitric acid — includes N₂O emissions.
• Production of adipic acid — includes N₂O emissions.
• Production of glyoxal and glyoxylic acid — includes N₂O emissions.
• Production of ammonia, bulk organic chemicals (cracking, reforming, partial or full oxidation), hydrogen and synthesis gas, soda ash, sodium bicarbonate.
• Capture of greenhouse gases for the purpose of transport and geological storage in a storage site permitted under Directive 2009/31/EC (the CCS Directive).
• Transport of greenhouse gases by pipelines for geological storage in a storage site permitted under Directive 2009/31/EC.
• Geological storage of greenhouse gases in a storage site permitted under Directive 2009/31/EC.
• Aviation (since 2012, with limited scope for intra-EEA and EEA-to-UK/Switzerland flights since 2013).
• Maritime transport (since 1 January 2024) — for vessels above 5,000 gross tonnage performing voyages between EU ports or stays in EU ports, plus 50% of emissions on voyages between an EU port and a non-EU port.

Threshold logic

The capacity thresholds matter. An installation only enters the ETS if it exceeds the Annex I threshold for at least one of its activities. A 15 MW combustion plant does not enter the ETS unless it is on the same site as another Annex I activity. A 25 MW combustion plant does enter, regardless of what other activities are on site. The aggregation rules (the “Annex I aggregation principle”) have substantial practical consequences for industrial sites with multiple sub-installations; the operative interpretation is in the Commission’s Guidance Document on Annex I scope.

Gases in scope

CO₂ across all in-scope activities. N₂O from nitric acid, adipic acid, and glyoxal/glyoxylic acid production. PFCs from primary aluminium production. CH₄ and N₂O from maritime transport from 1 January 2026. All other greenhouse gases (HFCs, SF₆, NF₃, methane outside maritime, N₂O outside the specific chemical sectors) are not covered by the EU ETS — for HFCs, PFCs, SF₆, and NF₃, the relevant EU instrument is Regulation (EU) 2024/573 (the F-Gas Regulation). See EU F-Gas Regulation 2024.

Geographic scope

EU 27 plus Iceland, Liechtenstein, and Norway under the European Economic Area Agreement. Switzerland operates a separate ETS that has been linked with the EU ETS since 1 January 2020, providing for mutual recognition of allowances and certificates. Northern Ireland’s electricity generators participate in the EU ETS under the Northern Ireland Protocol / Windsor Framework, while the rest of the UK operates the standalone UK ETS (see UK ETS divergence below).

The Cap-and-Trade Mechanism

The cap-and-trade mechanism is elegantly simple in concept and engineered into operational practice through a substantial body of secondary legislation. The annual sequence:

1. Cap setting. The Commission determines the annual EU-wide quantity of allowances under Article 9 of the directive, applying the Linear Reduction Factor and any rebasing adjustments to the prior year’s cap. The current year’s cap is published by Commission Decision before the start of each year.
2. Allocation. Free allocation to manufacturing installations is calculated under the Free Allocation Regulation (Commission Delegated Regulation (EU) 2019/331 as amended), based on the installation’s historical activity level (a five-year rolling average), the relevant product benchmark, and the carbon-leakage-exposure factor. The remaining allowances after free allocation are auctioned via EEX (and national platforms for Germany and historically Poland), with auction calendars published in advance by the auction platform.
3. Emissions. Over the calendar year, covered installations emit greenhouse gases. Each installation operates under an approved Monitoring Plan that specifies the methodology, measurement instrumentation, data sources, and tier requirements applicable to its activities.
4. Trading. EUAs trade continuously on the spot market and on the EEX, ICE Endex, and Nasdaq Oslo futures markets. December contracts are the principal liquidity venue (with concentration in the December contract closest to the compliance deadline). Trading is open to compliance entities, financial intermediaries, and non-financial market participants.
5. Reporting. By 31 March of the year following the emission year, the operator submits a verified Annual Emissions Report to the national competent authority, verified by an accredited verifier. The verified emissions figure is the legally binding number of EUAs the operator must surrender.
6. Surrender. By 30 September of the year following the emission year (formerly 30 April, shifted under the 2023 reform from compliance year 2024 onward), the operator surrenders the verified-emissions number of EUAs through the national registry account. Surrendered EUAs are cancelled.
7. Reconciliation. The EUTL reconciles surrendered EUAs against verified emissions across the EU. Operators with surrendered EUAs below verified emissions face an Excess Emissions Penalty of EUR 100 per tonne (indexed to 2013 levels, so approximately EUR 132 per tonne in 2026) plus the obligation to surrender the missing EUAs in the following compliance cycle. The financial penalty is in addition to, not instead of, the missing surrender.

The market price of an EUA emerges from the intersection of the supply curve — defined by the cap and the auction calendar — and the demand curve — defined by covered emissions, the operator’s free-allocation position, the operator’s banking and hedging strategy, and the financial-market positions taken by intermediaries. Because the cap is binding and absolute, the long-run equilibrium price is determined by the marginal abatement cost across the covered sectors that brings aggregate emissions down to the cap. The short-run price reflects expectations about future emissions, future cap trajectories, fuel-switching economics in the power sector, weather and macroeconomic shocks, and the operation of the Market Stability Reserve.

Phase 4 (2021–2030) and the Linear Reduction Factor

Phase 4 is the operative phase of the EU ETS until 31 December 2030. It was designed in two waves: the original Phase 4 design under Directive (EU) 2018/410 with a Linear Reduction Factor of 2.2% per year, and the substantially-revised Phase 4 architecture under Directive (EU) 2023/959, which raised the ETS sectoral target from a 43% reduction by 2030 (versus 2005) to 62% by 2030.

The Linear Reduction Factor

The LRF is the headline supply-tightening parameter. It is expressed as a percentage of the 2008–2012 baseline emissions, and it determines the year-on-year reduction in the EU-wide quantity of allowances. Under Directive (EU) 2023/959:

• 2021 to 2023: 2.2% per year (the originally-designed Phase 4 LRF).
• 2024 to 2027: 4.3% per year (the first elevated LRF under the 2023 reform).
• 2028 onwards: 4.4% per year (the second elevated LRF, applying through end-Phase 4 and into Phase 5 pending future revision).

The two rebasings

On top of the LRF, the 2023 reform imposed two one-off “rebasing” reductions to the cap, designed to bring the supply trajectory more sharply in line with actual emissions (which had fallen faster than the 2018-era LRF anticipated, particularly in the power sector following the post-2018 EUA price increase and the renewable-energy buildout):

• 2024: 90 million allowance reduction applied to the 2024 cap.
• 2026: 27 million allowance reduction applied to the 2026 cap.

The maritime expansion

To account for the inclusion of maritime transport in the EU ETS scope from 1 January 2024, the 2024 cap was simultaneously increased by 78.4 million allowances, based on the maritime sector’s average emissions reported for 2018 and 2019. The maritime cap expansion was netted against the 90 million rebasing reduction in 2024, with the net effect captured in Commission Decision (EU) 2023/1575 setting the 2024 Union-wide quantity at 1,386,051,745 allowances.

The Cap Trajectory Table

The table below summarises the EU-wide quantity of allowances (in million tonnes CO₂e, ETS1 stationary installations and maritime; aviation cap reported separately) for each year of Phase 4 as determined by the Commission Decisions and the Directive (EU) 2023/959 trajectory. Stationary installations + maritime; aviation reported separately because it has its own sub-cap calculation. All values are hardcoded to the Commission Decisions and the ICAP factsheet.

Year-by-year cap values for 2021–2023 and 2025 are approximate (rounded to the nearest million) because the 2023 reform’s rebasings and maritime inclusion required cap reconstruction that the Commission publishes in stages. For exact values for any specific year, consult the relevant Commission Decision under Article 9 of the directive published in the Official Journal.

The aviation sub-cap

Aviation operates under its own sub-cap, separately calculated. The aviation cap was historically 95% of average 2004–2006 emissions until Phase 4. From 2021, the aviation cap is also subject to the annual LRF. The 2026 aviation cap is 24.9 MtCO₂e. Free allocation to aircraft operators is fully phased out from 2026; over 2024–2030, 20 million aviation allowances are reserved to support sustainable aviation fuel uptake.

EUA Allocation — Free Allocation vs Auctioning

EUAs reach the market through two channels: free allocation to installations exposed to carbon leakage risk, and auctioning of the remaining allowances. The split between the two has shifted progressively toward auctioning over each phase, and the 2023 reform accelerated the shift further by phasing out free allocation for CBAM-covered sectors.

The default: auctioning

Auctioning is the default allocation method under Article 10 of the directive. EUAs are auctioned by EEX as the common auction platform for 25 Member States plus Iceland, Liechtenstein, and Norway, with separate national platforms for Germany. Auctions are held with high frequency — multiple auctions per week on EEX — with the auction calendar published in advance. The auction is a single-round, sealed-bid, uniform-price format; bidders submit price-quantity bids, and the clearing price is the highest bid that exhausts the auction volume. The auction reserve price is technical (linked to recent secondary market activity, intended to detect pricing anomalies) rather than a hard policy floor.

Auction revenue accrues to Member States in proportion to their share of the auctioned volume (with specific reservations for the Innovation Fund, the Modernisation Fund, and other EU-level instruments). Since June 2023, Member States are required to use all revenue from the EU ETS (or a financial equivalent) to support climate action and energy transformation.

Free allocation

Free allocation is reserved for manufacturing sectors at risk of carbon leakage — the risk that absent free allocation, EU producers would lose market share to imports from non-EU jurisdictions without equivalent carbon pricing, transferring rather than reducing global emissions. The free-allocation entitlement for an installation is calculated as the product of:

• Historical activity level — the rolling-average production volume over a defined reference period (5 years for the 2026–2030 allocation period, updated periodically to reflect actual production changes).
• Product benchmark — the harmonised EU-level benchmark for the relevant product (e.g. tCO₂/t hot metal for steel, tCO₂/t cement clinker, tCO₂/t primary aluminium). Benchmarks are set at the average of the top 10% most efficient installations producing the product in the EU, and reviewed periodically by the Commission.
• Carbon-leakage-exposure factor (CLEF) — for sectors on the carbon-leakage list, CLEF is 1.0 (full free allocation against benchmark and activity). For sectors not on the carbon-leakage list, the CLEF declines through the phase, reaching zero by the end of Phase 4 for most non-listed sectors.
• Linear Reduction Factor — the free-allocation entitlement is further reduced by the annual LRF.
• CBAM factor — for CBAM-covered sectors (iron and steel, cement, aluminium, fertilisers, electricity, hydrogen), the free-allocation entitlement is further reduced by the CBAM factor on the phase-out schedule below.
• Cross-sectoral correction factor (CSCF) — applied if the total free allocation across all installations exceeds the maximum free-allocation share of the cap (40% in Phase 4 since 2024). CSCF was 1.0 (no reduction) in 2021 to 2025; the Phase 4 cap includes a buffer of more than 450 million allowances earmarked for auctioning that can be made available if free-allocation volume is fully absorbed, avoiding triggering CSCF.

Conditionality from 2026

From 2026, free allocation for the second allocation period of Phase 4 is conditional on the operator implementing energy-efficiency measures based on audits or energy-management systems, and on implementing carbon-neutrality plans for the worst-performing installations — a measure designed to incentivise active decarbonisation rather than passive receipt of free allocation.

The carbon-leakage list

The carbon-leakage list is updated periodically by Commission Delegated Decision. The current list, applying for the 2021–2030 period, was set by Commission Delegated Decision (EU) 2019/708 and covers sectors and sub-sectors meeting quantitative thresholds for emission intensity and trade intensity with non-EU jurisdictions. Sectors on the list include most of the heavy-industrial sectors covered by Annex I activities: iron and steel, cement, lime, aluminium primary and secondary, copper, nickel, zinc, glass, ceramics, paper and pulp, chemicals (most categories), refining.

Free Allocation Phase-Out and the CBAM Schedule

The CBAM — Carbon Border Adjustment Mechanism — was adopted by Regulation (EU) 2023/956 on the same day as Directive (EU) 2023/959 and is the policy instrument that closes the carbon-leakage loophole in the EU ETS without requiring continued free allocation. The principle: as free allocation to EU producers in CBAM sectors phases out, CBAM phases in for imports of the same products, so EU and non-EU producers face equivalent carbon pricing at the EU market boundary.

The CBAM scope

CBAM covers six sectors as of May 2026: iron and steel, cement, aluminium, fertilisers, electricity, and hydrogen. The Commission has indicated future scope expansion (particularly to downstream goods containing CBAM precursors, and potentially to additional sectors based on the 2025–2026 review), but as of May 2026 the operative scope is the six sectors above. The CBAM definitive phase began on 1 January 2026; importers must hold CBAM certificates equivalent to embedded emissions in imported CBAM goods, with the first certificate-surrender obligation due 30 September 2027 for 2026 imports.

The free-allocation phase-out schedule

The CBAM factor (i.e. the percentage of free allocation withdrawn from CBAM sectors, and equivalently the percentage of CBAM certificate obligation applied to imports) follows the schedule below, hardcoded from Article 31 of CBAM Regulation (EU) 2023/956 and Article 10a of the amended ETS Directive:

The schedule is asymmetric: the phase-out begins at a slow rate before accelerating toward the end of the period. The slow start (2.5% / 5% / 10% across 2026–2028) is calibrated to give EU producers time to adapt and to allow CBAM enforcement infrastructure to bed in; the steep acceleration in 2029–2030 (22.5% to 48.5%) is the substantive transition phase; the 2030–2034 closure brings free allocation to zero. The Phase 5 architecture starting in 2031 will inherit a residual free-allocation regime for non-CBAM sectors on the carbon-leakage list, but the CBAM sectors’ transition will be complete by 2034.

The CBAM-ETS price coupling

CBAM certificates are priced at the weekly average of EU ETS allowance auction clearing prices, ensuring direct coupling between the CBAM cost and the operative EUA price. An importer of CBAM goods faces a marginal cost approximately equal to (embedded emissions per unit) × (CBAM factor) × (weekly EUA price) — less any carbon price already paid in the goods’ country of origin, where evidence of that payment can be provided. The economic effect is to equalise the carbon cost of EU and non-EU producers selling into the EU market.

Innovation Fund and Modernisation Fund

Auction revenue is the engine that funds two of the EU’s largest dedicated climate-investment instruments — the Innovation Fund and the Modernisation Fund. Together, these are the principal subsidy counterweight to the carbon price for projects that the carbon-price-alone signal would not commercially justify.

The Innovation Fund

The Innovation Fund supports demonstration of innovative low-carbon technologies. It is funded entirely by EU ETS auction revenue, with 530 million ETS allowances dedicated over Phase 4 (a substantial expansion versus the predecessor NER300 facility). Eligible activities include: highly innovative technologies and large-scale flagship projects within Europe that can bring on significant emission reductions; carbon capture and use; construction and operation of carbon capture and storage; innovative renewable energy generation technologies; energy storage. The Innovation Fund operates competitive calls; applications are assessed on degree of innovation, GHG emission avoidance potential, project maturity, scalability, and cost-efficiency.

In 2024, the Innovation Fund received EUR 2.4 billion in auction revenue, with a further share from CBAM revenues and additional allowances earmarked under the 2023 reform. Awards over 2020–2025 have spanned hydrogen production for industry, electric arc furnace steel-making, cement clinker substitution, CCS and CCU at industrial scale, and large-scale renewable energy deployment.

The Modernisation Fund

The Modernisation Fund supports modernisation of energy systems and improvement of energy efficiency in lower-income Member States — specifically the ten Member States with GDP per capita below 60% of the EU average (Bulgaria, Croatia, Czechia, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia), with Greece, Portugal, and Slovenia added under the 2023 reform on adjusted access conditions. The Fund is financed through the auctioning of 2.5% of the EU ETS cap across Phase 4 (with auctioning revenue redirected to recipient Member States rather than accruing to the originally-allocated Member State).

In 2024, the Modernisation Fund received EUR 6.3 billion in auction revenue. Cumulative Modernisation Fund disbursements over 2021–2024 exceeded EUR 17 billion, supporting renewable energy deployment, grid modernisation, energy efficiency, and just-transition investments in eligible Member States.

The Social Climate Fund

The Social Climate Fund — established by Regulation (EU) 2023/955 alongside the ETS Directive reform — is the third major auction-funded instrument, designed to support vulnerable households, micro-enterprises, and transport users disproportionately affected by ETS2 carbon-price exposure. The Fund is financed through the auctioning of 50 million EU ETS1 allowances plus revenues from ETS2 auctioning, with a 25% mandatory Member State co-contribution, totalling an expected EUR 86.7 billion between 2026 and 2032. Disbursements began in 2026 following the establishment of national Social Climate Plans.

The EUA Price — History and Drivers

The EUA price is the operative output of the EU ETS market. It is the marginal cost of compliance for any covered entity, the marginal benefit of any abatement project, and the operative carbon-price signal that ripples through European energy markets, industrial capex, corporate financial planning, and (since the CBAM coupling) the EU’s trade interface with third countries.

Annual average EUA price series

The table below documents the annual average EUA auction clearing price from the operative Phase 3 onward, sourced from the Commission’s annual Carbon Market Reports, the ESMA Carbon Markets Reports, and EEX auction summary data. The pre-2018 era is characterised by structurally low prices (driven by Phase 2 oversupply, the 2008 financial crisis demand drop, and slow MSR implementation); the 2018–2023 era is the price rally driven by the 2018 reform, the Green Deal, the post-COVID rebound, and Russia’s invasion of Ukraine; the 2024–2025 period is the post-rally correction.

The principal price drivers

Four structural drivers and several short-run drivers determine the EUA price.

Structural driver 1 — the cap trajectory. The LRF and the rebasings define the long-run supply curve. The 2024 LRF step-up and rebasings have already mechanically tightened supply relative to a 2.2%-LRF counterfactual; the 2028 LRF step-up to 4.4% will tighten further. Long-run prices reflect market expectation about marginal abatement cost in the tightening-supply regime.

Structural driver 2 — the MSR. The Market Stability Reserve absorbs surplus when TNAC exceeds 833 million allowances at a 24% intake rate maintained until 2030, then 12% thereafter under current law. The MSR has already invalidated 3.2 billion allowances since 2023, a structural tightening of approximately 30% of a typical annual cap.

Structural driver 3 — CBAM coupling. The phase-out of free allocation for CBAM sectors transfers demand for EUAs from “free issuance” to “auction purchase”, raising effective demand at any given underlying emissions volume.

Structural driver 4 — the underlying emissions trajectory. 2023 saw a record 15.6% decline in EU ETS emissions versus 2022, driven by renewable energy expansion and gas substitution in the power sector. Continued power-sector decarbonisation reduces underlying demand for EUAs, putting downward pressure on prices through the 2024–2025 correction.

Short-run drivers include: weather (mild winters reduce heating demand for fossil fuels in covered installations); fuel-price relativities (the gas-coal switch price in the power sector); macroeconomic activity in heavy industry; speculative positioning by financial market participants (with the ESMA Carbon Markets Report 2025 documenting a substantial financial-intermediary role in price discovery); regulatory and policy news flow.

The Market Stability Reserve (MSR)

The Market Stability Reserve, established by Decision (EU) 2015/1814 and operational from 1 January 2019, is the EU ETS’s structural surplus-management mechanism. It exists because a binding cap on emissions does not, by itself, deliver a binding price floor — an oversupply of allowances (whether from cap miscalibration, demand collapse, or backloading) can drive prices toward zero, eroding the abatement signal. The MSR fixes this by quantitative intervention: when the Total Number of Allowances in Circulation (TNAC) exceeds a defined upper threshold, a percentage of TNAC is withdrawn from the auction calendar and held in the reserve, with the withdrawn allowances eventually invalidated (cancelled, not re-released) under the 2023 reform.

How it works

The TNAC is published annually by the Commission, based on the cumulative supply (auctioned + freely allocated + reserve releases) minus the cumulative demand (surrendered + cancelled) since 2008. The triggers:

• Upper threshold: TNAC above 833 million allowances triggers MSR intake.
• Intake rate: 24% of TNAC is transferred into the MSR until 2030, scheduled to revert to 12% from 2031 under current law (the 2023 reform retained the 24% rate for an extended period; the rate stays at 24% until 2030, then drops to 12% thereafter unless further amended).
• Lower threshold: TNAC below 400 million allowances triggers release of 100 million allowances from the MSR back into auctions (the inverse symmetric backstop, not used in operative experience).
• Invalidation: Under the 2023 reform, allowances held in the MSR above defined levels are permanently invalidated (cancelled), not just held. The MSR has invalidated 3.2 billion allowances since 2023.

Why the MSR is structurally tighter than the LRF alone

The MSR does not just defer supply — it permanently removes supply when invalidation conditions are met. This makes the effective cap trajectory tighter than the LRF alone implies, with the precise tightening depending on the operative TNAC trajectory. The 3.2 billion allowances invalidated since 2023 represent roughly 30% of a typical annual cap and have been a structural driver of the post-2018 price rally.

The 2023 reform changes

The 2023 reform retained the 24% intake rate until 2030, added an automatic-release mechanism in the event of “excessive price fluctuations” (where prices spike above a defined multiple of the trailing two-year average for six consecutive months, additional allowances are released from the MSR to dampen the spike), and tightened the TNAC calculation by adjusting for maritime emissions inclusion and other scope changes.

MRV — Monitoring, Reporting, and Verification

The Monitoring, Reporting, and Verification regime is the operational backbone of the EU ETS. It is what makes the verified emissions number on which surrender obligations depend a defensible, audit-grade quantity. The MRV regime is the substantive content of two principal regulations: Commission Implementing Regulation (EU) 2018/2066 (the Monitoring and Reporting Regulation, “MRR”) and Commission Implementing Regulation (EU) 2018/2067 (the Accreditation and Verification Regulation, “AVR”).

The installation Monitoring Plan

Every covered installation operates under a Monitoring Plan approved by the national competent authority. The Monitoring Plan specifies, for each source stream (fuel input, process emission source) at the installation:

• The methodology applied — calculation-based (combining activity data with emission factors) or measurement-based (continuous emissions monitoring system, CEMS).
• The tier level applied for each parameter — activity data, calorific value, emission factor, oxidation factor, conversion factor — from tier 1 (lowest precision, default values acceptable) to tier 4 (highest precision, operator-specific values determined by laboratory analysis with defined frequency).
• The measurement instrumentation, including calibration and quality-assurance regime.
• The data flow from raw measurement to the reported number, with the responsibilities of personnel involved.
• The treatment of biomass (which carries an emission factor of zero where the biomass meets the sustainability and GHG-saving criteria in Annex IV of the MRR).

Tier requirements by installation size

The MRR specifies minimum tier requirements that scale with installation size (Category A: <50,000 tCO₂e/year; Category B: 50,000–500,000 tCO₂e/year; Category C: >500,000 tCO₂e/year). Higher-emitting installations must use higher tiers, with deviation only permitted where technical or financial infeasibility is demonstrated to the competent authority.

The verifier’s role

The verifier — an accredited body operating under the AVR — performs a risk-based audit of the operator’s Annual Emissions Report against the Monitoring Plan, the underlying data flow, and a sample of source documents. The verifier’s opinion is “verified”, “verified with comments”, or “not verified”. Only “verified” reports are operative for compliance; “verified with comments” requires resolution of the comments before the competent authority accepts the report; “not verified” reports require remediation and resubmission.

Verifier accreditation is by sector (the verifier must be accredited for the specific Annex I activity scope of the installation) and verifier independence is governed by AVR provisions on conflict of interest, rotation, and quality-management requirements compliant with ISO/IEC 17029.

The Compliance Cycle and 30 September Surrender Deadline

The compliance cycle is the operator’s annual rhythm. The shift in surrender deadline under the 2023 reform — from 30 April to 30 September — is one of the most operationally consequential changes of the reform, giving operators an additional five months between verified-emissions reporting (still 31 March) and surrender, easing treasury planning and reducing the seasonal concentration in EUA demand.

The annual cycle

1. 1 January – 31 December (year Y): Emission year. Operator emits under the Monitoring Plan.
2. By 31 March (year Y+1): Operator submits Verified Annual Emissions Report (year Y emissions) to competent authority, verified by accredited verifier.
3. By 30 April (year Y+1): Free allocation for year Y+1 issued to operator-holding accounts in national registry (where eligible).
4. By 30 September (year Y+1): Operator surrenders EUAs equal to verified year Y emissions through the national registry. Pre-2024 deadline was 30 April; shifted to 30 September from compliance year 2024 onward.
5. 30 September (year Y+1) onwards: EUTL reconciles surrendered EUAs against verified emissions. Operators with deficit face Excess Emissions Penalty.

The Excess Emissions Penalty

Under Article 16(3) of the directive, operators failing to surrender EUAs covering verified emissions face a penalty of EUR 100 per excess tonne (indexed for inflation from 2013, reaching approximately EUR 132 per tonne by 2026). The penalty is in addition to the obligation to surrender the missing allowances in the following compliance cycle — the operator does not “buy out” the surrender obligation through the penalty. Names of operators failing to surrender on time are published, providing a reputational sanction alongside the financial one.

Treasury implications

The shift to 30 September has substantial treasury-management consequences for covered operators. The five-month gap between verified-emissions reporting and surrender means an operator can plan EUA purchases against actual verified emissions rather than estimates, reducing forecast risk in EUA budgeting. The September concentration of surrender activity also reshapes the EUA futures market: the December contract still dominates trading liquidity, but the September-to-December rollover dynamic has shifted, with implications for hedging strategies.

The EU Transaction Log (EUTL) and National Registries

The EUTL is the central transaction-recording infrastructure for the EU ETS, operated by the European Commission. It records, in real time, every EUA transaction across all national registries: issuances of free allocation, auctioning outcomes, transfers between operator-holding accounts, transfers from operator accounts to trading platforms, surrenders against verified emissions, and cancellations.

Each Member State operates a national registry as a sub-system of the EUTL, hosting the operator-holding accounts for installations and aircraft operators within its jurisdiction. The national registry is the interface through which an operator surrenders allowances, receives free allocation, and conducts transactions. National-registry account-holders are subject to identity-verification (KYC) requirements operated by the Member State authority; trading-platform participants and intermediaries hold accounts in their own right with separate documentation requirements.

The EUTL also operates the EU Transaction Log public interface, providing transparency on free allocation by installation, verified emissions by installation, surrendered allowance volume by installation, and a comprehensive installation-by-installation historical record. This is the operative dataset for any researcher, analyst, or compliance practitioner needing installation-level emissions history.

ETS2 — Buildings, Road Transport, and Additional Fuels

ETS2 is the second, parallel emissions trading system introduced by Directive (EU) 2023/959 to extend carbon pricing to sectors that the existing ETS does not cover — principally road-transport fuels, buildings heating fuels, and small-industry fuels not already covered by ETS1. ETS2 is upstream: the regulated entity is the fuel supplier (typically a tax warehouse-keeper or fuel distributor with excise-duty registration), not the end consumer. The fuel supplier monitors and reports the GHG content of the fuels it places on the market and surrenders allowances against that GHG content.

The launch timeline

Originally scheduled to begin compliance in 2027, ETS2 was postponed to 2028 by EU Council and Parliament decision in March 2026 in response to energy-price concerns. The operative timeline as of May 2026:

• 1 January 2025: Monitoring of ETS2 emissions begins. Fuel suppliers in scope must establish Monitoring Plans and begin recording fuel-supply-emission data.
• 30 April 2025: First (unverified) emission reports submitted for 2024 covered emissions.
• 2026: Verification of emission reports by accredited verifiers begins (for 2025 emissions). Social Climate Fund launched with EUR 50 billion frontloaded.
• 1 January 2027: Early auctioning of ETS2 allowances begins (as proposed by the Commission on 8 December 2025 following the postponement decision). Sale of 450 million EUA2s for the Social Climate Fund begins.
• 1 January 2028: ETS2 compliance begins. First ETS2 emission year for surrender purposes.
• 30 April 2029: First verified ETS2 Annual Emissions Reports submitted (for 2028 emissions).
• 31 May 2029: First ETS2 allowance surrender deadline (for 2028 emissions).

The cap and trajectory

The ETS2 cap is set to deliver a 42% reduction in covered emissions by 2030 compared to 2005. The cap trajectory uses a higher LRF than ETS1: 5.10% from 2024 and 5.38% from 2028. The 2027 emission cap was set at 1,036 MtCO₂e (published 3 December 2024 by the Commission).

Pricing and stability mechanisms

ETS2 has its own dedicated Market Stability Reserve operating on a rule-based mechanism distinct from the ETS1 MSR. The 2023 reform also introduced Article 30h price stability provisions for ETS2 that can release additional allowances if prices exceed defined thresholds at the start of the system — an “energy price safeguard” reflecting concerns about ETS2 cost incidence on vulnerable consumers. Allowances in ETS2 are not fungible with ETS1 allowances; the two markets are separate.

The Commission’s pre-launch impact-assessment expected ETS2 prices in the EUR 45–80 range over 2027–2030. Early secondary-market futures (December 2028 contracts traded on ICE and EEX from mid-2025) have generally tracked at the lower end of that range, with the postponement to 2028 compressing forward expectations.

ETS1 vs ETS2 Disambiguation

Practitioners regularly confuse ETS1 and ETS2 because both systems use the language of “EU ETS” interchangeably. The table below is the disambiguation reference.

Aviation in the EU ETS

Aviation entered the EU ETS in 2012 under Directive 2008/101/EC, originally with global scope (all flights to and from EEA airports) but limited in practice from 2013 to intra-EEA flights and from departing flights to Switzerland and the United Kingdom following pushback from non-EEA jurisdictions and the development of ICAO’s CORSIA scheme.

The current aviation scope

As of May 2026, the EU ETS covers aviation emissions from:

• All intra-EEA flights (departing and arriving within the EU 27, Iceland, Liechtenstein, Norway).
• Departing flights from the EEA to Switzerland (linked under the EU–Switzerland ETS linkage).
• Departing flights from the EEA to the United Kingdom (under the EU–UK Trade and Cooperation Agreement; the UK ETS applies to UK-to-EEA flights).
• Most flights to and from the EU’s nine outermost regions, plus departing flights from these regions to Switzerland and the UK (under the 2023 reform).

The intra-EEA scope is maintained through end-2026, after which the Commission will assess whether to extend the scope to extra-EEA international flights in light of CORSIA’s operational performance.

CORSIA interaction

CORSIA — the Carbon Offsetting and Reduction Scheme for International Aviation, administered by ICAO — covers international flights between participating states. The EU ETS applies to flights within its scope; CORSIA applies to international flights covered by CORSIA between countries that participate. The two schemes are reconciled through the EU regulation implementing CORSIA (Regulation (EU) 2025/108 and successor instruments), with EU air operators applying CORSIA offsetting only to flights outside the EU ETS scope.

Free allocation phase-out

Aviation free allocation was reduced to 25% in 2024 and 50% in 2025 (declining), then fully phased out from 2026. Over 2024–2030, 20 million allowances from the aviation cap are reserved to support sustainable aviation fuel uptake.

Maritime in the EU ETS

Maritime entered the EU ETS on 1 January 2024 under Directive (EU) 2023/959, the most significant scope expansion in the system’s history. The maritime regulation operates on a vessel-and-voyage basis rather than installation-based, with shipping companies (the “compliance entities”) responsible for surrendering allowances against verified emissions.

The maritime scope

Vessels of 5,000 gross tonnage and above, regardless of flag, performing the following voyages:

• 100% of emissions on voyages between two EU ports.
• 100% of emissions during stays in EU ports.
• 50% of emissions on voyages between an EU port and a non-EU port (departing or arriving).

Initially limited to CO₂ emissions only; CH₄ and N₂O emissions added from 2026. Government non-commercial vessels (military, emergency services) and certain fishing-vessel categories are excluded.

The phase-in schedule

Maritime surrender obligations phase in across 2025–2027 to give the sector time to adapt to the new compliance obligation:

• 2024 emissions, surrendered in 2025: 40% of verified emissions.
• 2025 emissions, surrendered in 2026: 70% of verified emissions.
• 2026 emissions, surrendered in 2027: 100% of verified emissions.

To ensure environmental integrity during the phase-in, Member States will cancel the number of allowances equivalent to the difference between surrendered allowances and verified emissions in 2024 and 2025 — effectively removing the un-surrendered share permanently from circulation rather than carrying forward a free-rider position.

MRV under MRV Maritime

Maritime MRV is operated under Regulation (EU) 2015/757 (the MRV Maritime Regulation) as substantially amended for ETS purposes. Shipping companies must develop vessel-specific Emissions Monitoring Plans, appoint accredited verifiers, and submit verified annual emissions reports. The administering Member State for each shipping company is determined by the country of the company’s registered office (for EU-flagged operators) or by the country whose ports the company visits most frequently (for non-EU-flagged operators).

CBAM — Carbon Border Adjustment Mechanism

CBAM is the EU’s third pillar of carbon-leakage protection alongside free allocation and Member State indirect-cost compensation. It was established by Regulation (EU) 2023/956, adopted on the same day as the ETS Directive reform, and operates as the carbon-border-pricing instrument that ensures imports of carbon-intensive goods face equivalent carbon pricing to EU-domestic production.

CBAM sectors

As of May 2026, CBAM covers six sectors: iron and steel, cement, aluminium, fertilisers, electricity, and hydrogen. The Commission has signalled scope expansion to additional sectors (potentially including organic chemicals, plastics, and downstream products containing CBAM precursors), but as of May 2026 the operative scope is the six sectors. Importers of CBAM goods become “authorised CBAM declarants” (registered with the national competent authority) and submit annual CBAM declarations by 31 May each year, reconciling embedded emissions to CBAM certificates surrendered.

The two phases

Transitional phase (1 October 2023 to 31 December 2025). Quarterly reporting of embedded emissions in imported CBAM goods, with no financial obligation. The transitional phase was the data-collection and infrastructure-bedding-in period.

Definitive phase (1 January 2026 onwards). Importers must hold CBAM certificates equivalent to embedded emissions adjusted for the CBAM factor and for any carbon price already paid in the country of origin. CBAM certificates are priced at the weekly average EU ETS auction clearing price, ensuring direct ETS–CBAM coupling.

The CBAM declaration

By 31 May each year, the authorised CBAM declarant submits a CBAM declaration covering the previous calendar year’s imports, identifying for each consignment:

• The CBAM goods imported (CN code), quantity, country of origin.
• Embedded emissions (direct and, from 2026, indirect emissions for electricity-intensive products), based on verified actual installation-level data or on default values published by the Commission.
• Any carbon price paid in the country of origin and verified by independent verification.
• The number of CBAM certificates the declarant has surrendered (or proposes to surrender by 30 September of the following year) to cover the obligation.

Default values mark-up

Where the importer cannot obtain verified actual installation-level emissions data from the producer, the importer may use default values published by the Commission in Implementing Regulation (EU) 2025/2621. Default values carry a mark-up of 10% above country-specific averages in 2026, rising to 20% in 2027 and 30% from 2028 onward, making actual-data sourcing progressively more economically attractive relative to default-value use.

How EU ETS Maps to GHG Protocol Scope 1

For sustainability officers, the EU ETS verified emissions number is the highest-quality available data point for the corporate Scope 1 inventory at any covered installation — verified by an independent accredited body, calculated under a tier-rich regime with documented quality assurance, and reconciled against fuel-purchase records and process-flow data. The relationship between ETS verified emissions and corporate Scope 1 inventory is one of nested data flows with specific reconciliation requirements.

The boundary alignment

The EU ETS boundary is the installation (or aircraft operator, or shipping company). The GHG Protocol Scope 1 boundary is the reporting entity — the company that owns or operates the installation under either the operational-control or financial-control approach. The two boundaries align where the reporting entity directly operates the installation; they diverge where the installation is operated under a joint venture, lease, or operating arrangement that puts the legal compliance obligation under one entity and the operational or financial control under a different reporting entity.

Three reconciliation steps

For a multi-site operator with ETS-covered installations:

1. Extract verified emissions per installation from the EU ETS Annual Emissions Reports for the reporting year.
2. Aggregate across the operational footprint applying the chosen consolidation boundary (operational control or financial control under GHG Protocol). Each installation’s verified emissions enter the inventory once, allocated to the consolidating entity.
3. Add non-ETS Scope 1 sources — the bulk of which are: smaller combustion units below the 20 MW threshold; mobile combustion in owned or leased vehicles; refrigerant fugitive emissions (see EU F-Gas Regulation); other non-Annex-I sources. These are calculated using the operator’s own data and standard emission factors from DEFRA, IPCC, or other recognised sources.

GWP basis

The ETS MRR has been updated to use IPCC AR6 GWP-100 values for N₂O, PFC, and maritime CH₄/N₂O CO₂e conversions. This aligns the ETS MRV regime with the GHG Protocol’s current GWP-100 expectation and with the ESRS E1-6 disclosure stack — a notable contrast with the F-Gas Regulation, which uses IPCC AR4 GWP-100 values for its internal CO₂e calculations (see EU F-Gas Regulation for that divergence).

Data quality

ETS-verified emissions are GHG Protocol Tier 1 data quality (highest), reconciled to physical activity data and process documentation, audited by an independent accredited verifier, and subject to penalty for misrepresentation. For ETS-covered installations, an operator reporting Scope 1 using anything other than ETS-verified emissions has unambiguously taken a downgrade in data quality and is exposed to inventory inconsistency between the verified ETS submission and the published corporate disclosure.

EU ETS and CSRD ESRS E1 Disclosure

Under the Corporate Sustainability Reporting Directive (Directive (EU) 2022/2464), in-scope undertakings must publish ESRS-compliant sustainability disclosures, with ESRS E1 Climate Change as the principal climate-disclosure standard. EU ETS exposure shows up at three distinct points in the ESRS E1 disclosure chain:

ESRS E1-6 gross Scope 1 emissions

The ETS verified emissions feed directly into the ESRS E1-6 gross Scope 1 disclosure. For ETS-covered installations, the audit chain runs from the verified Annual Emissions Report through the corporate inventory database to the ESRS E1-6 line. The CSRD-required limited assurance (and forthcoming reasonable assurance) on E1-6 is materially eased by the existence of the ETS verification, which provides an independent verification trail upstream of the assurance scope. See CSRD / ESRS E1.

ESRS E1-7 GHG removals and carbon-credit projects

Where an operator holds EUAs purchased at auction for surrender against verified emissions, those EUAs are not “carbon credits” in the ESRS sense — they are compliance instruments. Where an operator surrenders allowances above and beyond compliance (effectively “cancelling” excess EUAs as a voluntary additional climate action), the cancellation can be characterised under ESRS E1-7 with appropriate disclosure of the basis. Most operators do not voluntarily cancel EUAs.

ESRS E1 carbon price exposure as material financial risk

The principal CSRD touchpoint for EU ETS is in the financial-risk-disclosure dimensions of ESRS E1, including the transition plan (E1-1), the policies and actions (E1-2, E1-3), the targets (E1-4), and the financial effects of climate-related risks (E1-9). An operator with material EUA exposure must disclose:

• The current EUA position (free-allocation entitlement vs verified emissions and the EUA deficit or surplus).
• The forward EUA exposure projection across the transition plan horizon (typically 2030 / 2040 / 2050) under multiple price scenarios.
• The mitigation strategy (abatement projects, hedging book, free-allocation conditionality compliance, fuel-switching, CCS).
• The accounting treatment of EUAs held for surrender (typically as intangible assets under IAS 38 or as inventory under IAS 2, with measurement basis disclosed).
• The financial impact of the CBAM phase-out on free allocation for CBAM-sector operators.

This is one of the highest-priority financial-risk disclosures for EU heavy-industry CSRD reporters, and the depth of disclosure expected by EFRAG and by financial-market assurance providers has increased materially with each reporting cycle.

EU ETS and SBTi — Beyond-Compliance Target Setting

For operators committed to Science Based Targets, the EU ETS cap trajectory is not, by itself, a sufficient target. SBTi’s Corporate Net-Zero Standard requires near-term Scope 1+2 reductions of at least 42% by 2030 from a recent base year for 1.5°C-aligned targets, and long-term reductions of at least 90% by 2050. The ETS cap trajectory (62% reduction by 2030 vs 2005 for the covered sectors in aggregate) is sector-wide, not company-specific; an individual operator’s actual reduction can be substantially above or below that aggregate.

Why SBTi targets must go beyond ETS compliance

Three reasons. First, ETS compliance can be achieved by purchasing allowances on the market rather than by physical abatement — an operator that buys EUAs to cover its emissions has “complied” but has not “reduced”. SBTi requires actual emissions reductions, not market-based compliance. Second, the ETS cap trajectory is the aggregate of all covered sectors; an individual operator’s pathway must be aligned with the sectoral pathway in the SBTi framework, which for heavy industry typically requires reductions steeper than the ETS average. Third, SBTi targets are total-corporate footprint targets including non-ETS Scope 1, all Scope 2, and (for many operators) Scope 3 — a boundary substantially wider than the ETS-covered installations.

The base-year recalculation question

SBTi requires base-year recalculation when structural changes (acquisitions, divestments, calculation-methodology changes) materially affect base-year emissions. The shift from AR5 to AR6 GWP-100 values in the ETS MRR is a calculation-methodology change that, where it materially affects the operator’s inventory, triggers SBTi base-year recalculation. For operators whose Scope 1 is dominated by CO₂ from fossil-fuel combustion (most ETS power-sector and heavy-industry operators), the AR5-to-AR6 shift is immaterial for CO₂; for operators with significant N₂O or HFC fugitive emissions, the shift can be material and recalculation is required. See SBTi Corporate Net-Zero Standard and SBTi readiness checklist.

The decarbonisation-pathway alignment

For ETS-covered operators, the SBTi alignment exercise typically proceeds by: (1) extracting the SBTi sectoral decarbonisation pathway (typically the Steel, Cement, Aluminium, Chemicals, or Power sector pathways under the Sectoral Decarbonization Approach); (2) reconciling against the operator’s current ETS verified emissions and free-allocation position; (3) building the project pipeline (electrification, hydrogen, CCS, low-carbon raw materials) that closes the gap between the ETS-compliance pathway and the SBTi-aligned pathway; (4) submitting the target for SBTi validation with the supporting evidence on emissions data, target boundary, and reduction pathway.

Worked Example — Annual Compliance Cycle for a Cement Plant

The following walks through a stylised annual compliance cycle for a mid-size cement plant in the EU, covering the verified emissions, free allocation, surrender obligation, EUA purchase requirement, financial cost, and CSRD disclosure values. The example is illustrative; real installation values vary widely by clinker production capacity, fuel mix, alternative-raw-material substitution, and free-allocation entitlement.

The plant

A cement plant with rotary-kiln clinker production capacity of 1.8 million tonnes per year, operating in Germany under a greenhouse-gas-emissions permit issued by the Umweltbundesamt (German Federal Environment Agency, the national competent authority). Annex I activity: production of cement clinker in rotary kilns with capacity exceeding 500 tpd. CBAM sector: yes (cement is one of the six CBAM sectors).

Year 2025 verified emissions

Verified 2025 emissions (submitted by 31 March 2026, verified by an accredited verifier): 1.05 million tCO₂e. Calculated under the Monitoring Plan combining: process emissions from raw-meal calcination (carbonate decomposition; ~60% of total); fuel combustion in the kiln (coal, petcoke, alternative fuels including waste-derived fuels and biomass; ~40% of total); biomass content of alternative fuels carried at zero emission factor under MRR Annex IV.

Free allocation entitlement for 2025

Free allocation calculated under the Free Allocation Regulation:

• Historical activity level (HAL): 1.62 million tonnes of clinker per year (5-year rolling average over 2018–2022).
• Product benchmark for cement clinker (2024–2030 period): 0.693 tCO₂/t clinker.
• Carbon-leakage exposure factor (CLEF): 1.0 (cement is on the carbon-leakage list).
• LRF reduction for 2025 (versus baseline allocation): ~6.5% cumulative since 2024.
• CBAM factor 2025: not applicable (CBAM phase-out begins 2026).

Base entitlement: 1.62M × 0.693 = 1.123M EUAs. After LRF reduction: approximately 1.05M EUAs. Free allocation for 2025: ~1.05 million EUAs.

The surrender position

Verified emissions: 1.05 million tCO₂e. Free allocation: 1.05 million EUAs. Net surrender position: approximately balanced — the plant surrenders its free allocation, with neither a material deficit nor surplus. For a typical mid-2020s European cement plant on the carbon-leakage list with full CLEF and operating near benchmark efficiency, this is approximately the operative position.

Year 2026 transition: CBAM factor begins

For 2026 emissions (surrendered in 2027), the CBAM factor of 2.5% withdraws 2.5% of the free-allocation entitlement. The 2026 free allocation: approximately 1.05M × (1 − 0.025) × (1 − LRF) = ~1.0 million EUAs. Assuming verified 2026 emissions of 1.05M (constant), the operator has a surrender deficit of ~50,000 EUAs that must be purchased.

At an EUA price of EUR 75/tCO₂e (the operative mid-2026 range), the EUA-purchase cost: 50,000 × EUR 75 = EUR 3.75 million. This is the operator’s “marginal carbon cost” for 2026 — the cost above and beyond the value of free allocation.

The 2030 cliff edge

The same exercise repeated for 2030 (CBAM factor 48.5%, LRF cumulative reduction approximately 31% from 2024 baseline): free allocation drops to approximately 1.05M × (1 − 0.485) × (1 − 0.31) = ~373,000 EUAs. Surrender deficit (assuming constant 1.05M emissions): ~677,000 EUAs. At EUR 100/tCO₂e (a plausible 2030 price scenario): EUR 67.7 million annual marginal carbon cost.

The 2030 number is the operative driver of cement-sector capex decisions today: invest in clinker substitution (calcined clay, supplementary cementitious materials), in alternative-fuel substitution, in CCS or in cementicious-binder alternatives, before the 2030 free-allocation cliff arrives. The cement-sector industry response — including the EU Cement Decarbonisation Initiative and the operator-level investment commitments by major producers — reflects this calculation.

CSRD disclosure

The operator’s CSRD ESRS E1 disclosure includes: gross Scope 1 emissions of 1.05M tCO₂e (E1-6); the EUA holding position at year-end; the EUA-purchase cost for the year; the forward EUA-exposure projection across the transition plan horizon (typically to 2030 / 2040 / 2050) under multiple ETS-price scenarios; the project pipeline and capex for sector decarbonisation; the projected emissions trajectory aligned with the cement-sector SBTi pathway.

Note: values are illustrative for methodology demonstration. Actual plant emissions, free allocation, prices, and project pipelines vary widely. Use installation-specific verified data, not these example values, for any real reporting or planning position.

UK ETS Divergence and the EU–UK Linkage Negotiation

The United Kingdom left the EU ETS at the end of the Brexit transition period on 31 December 2020 and established the standalone UK Emissions Trading Scheme under the Greenhouse Gas Emissions Trading Scheme Order 2020 (SI 2020/1265) effective 1 January 2021. Northern Ireland’s electricity generators continue to participate in the EU ETS under the Northern Ireland Protocol / Windsor Framework, while the rest of the UK operates the UK ETS.

The substantive divergence as of May 2026

The UK ETS replicates much of the EU ETS architecture (cap-and-trade, free allocation against benchmarks, auctioning, verifier-based MRV) but has diverged substantively in several dimensions:

• Cap: The UK ETS cap was originally set 5% below the UK’s notional share of the EU ETS Phase 4 cap, then reduced further in 2024 to align with the UK’s net-zero-by-2050 target. The 2026 cap is 77.4 MtCO₂e.
• Auction Reserve Price: The UK ETS has a hard auction reserve price (the EU ETS does not). The ARP rises from GBP 22 to GBP 28 in 2026, then increases yearly with inflation from 2027. The EU ETS has no equivalent floor.
• Cost Containment Mechanism: The UK ETS has a price-triggered Cost Containment Mechanism (the EU ETS has the quantity-based MSR). The CCM triggers if the price exceeds three times the trailing two-year average for six consecutive months.
• No Supply Adjustment Mechanism: The UK ETS Authority decided in November 2025 to discount the implementation of a quantity-triggered Supply Adjustment Mechanism for a standalone UK ETS, retaining the price-based mechanisms.
• Sectoral scope: UK ETS does not currently cover maritime, road transport, or buildings (no UK ETS2 equivalent). Maritime inclusion is scheduled from 1 July 2026 for domestic voyages. Waste incineration inclusion from 2028.
• Free allocation phase: The second free allocation period was deferred from 2026 to 2027 to align with UK CBAM. A gradual phase-out of free allocations for UK CBAM sectors begins in 2027, with an indicative nine-year trajectory.
• UK CBAM: Effective 1 January 2027, covering iron/steel, cement, aluminium, fertilisers, hydrogen. Glass and ceramics excluded at launch despite the original proposal. Indirect emissions excluded until 2029.

UKA price divergence

The UK Allowance (UKA) price has diverged materially from the EU ETS EUA price since the systems split in 2021. UKA prices have typically traded below EUA prices — the official UK carbon-price-for-civil-penalties figure for 2025 was GBP 41.84 versus 2024 EUA average of EUR 65. The divergence reflects the smaller and less liquid UK market, the additional Carbon Price Support paid by UK power generators on top of UKA, and broader differences in cap tightness and macroeconomic conditions.

The EU–UK linkage negotiation

On 19 May 2025, the EU and the UK agreed to work toward establishing a link between the EU and UK ETSs. A linkage would provide for mutual recognition of allowances (UK installations could surrender EUAs against UK ETS verified emissions and vice versa), mutual CBAM exemption (UK exports to the EU would not face CBAM, equivalent to the Swiss exemption that exists since the EU–Switzerland linkage of 2020), and creation of a single EU–UK carbon market.

The UK ETS Authority’s December 2025 decision to drop the Supply Adjustment Mechanism and adopt EU benchmarks from 2028 were explicitly framed as preparing the UK ETS for linkage. The EU Council granted the Commission a negotiating mandate in 2025. As of May 2026, the linkage negotiation is ongoing; no operative agreement has been reached, and no implementation timeline has been announced.

Cross-border operator compliance

Operators with installations in both EU and UK jurisdictions (common in chemicals, refining, steel, cement, and aviation) must maintain dual compliance:

• EU installations: EU ETS permit, EU Monitoring Plan, verified EU Annual Emissions Report, EUA surrender by 30 September.
• UK installations: UK ETS permit, UK Monitoring Plan, verified UK Annual Emissions Report, UKA surrender by 30 April.
• Cross-EU/UK flights: EU ETS scope for departing EEA-to-UK; UK ETS scope for departing UK-to-EEA.
• CBAM: EU CBAM on UK exports to EU; UK CBAM on EU exports to UK from January 2027 (subject to UK CBAM–EU ETS linkage considerations).

Carbon Price Scenarios to 2030 and 2050

For corporate financial planning, capex decisions, transition plan disclosure, and SBTi target validation, the EUA price projection over the planning horizon matters as much as the current spot price. The principal scenario sets used in practice:

IEA scenarios

The IEA’s World Energy Outlook publishes annual scenario projections, including the Stated Policies Scenario (STEPS, current policy momentum), the Announced Pledges Scenario (APS, fully implemented government pledges), and the Net Zero Emissions by 2050 (NZE, 1.5°C-aligned). In the IEA WEO 2025 (published October 2025), the carbon price projections for advanced economies including the EU run approximately: STEPS — EUR 90 by 2030, EUR 130 by 2050; APS — EUR 120 by 2030, EUR 200 by 2050; NZE — EUR 140 by 2030, EUR 250 by 2050.

BNEF EU carbon price outlook

BloombergNEF publishes quarterly EU carbon price forecasts. The operative BNEF central scenario as of Q1 2026 projects EUA prices in the EUR 90–110 range by 2030 in a central-policy-momentum case, with upside scenarios pushing EUR 140 if the 2040 90% target is adopted with binding ETS implications and downside scenarios in the EUR 60–75 range if EU policy momentum weakens.

European Commission impact-assessment projections

The Commission’s impact assessments accompanying the Fit for 55 package projected EUA prices of approximately EUR 80–100 by 2030 under the central scenario. The 2024–2025 price correction has placed actual prices below the Commission central projection, with the recovery to the EUR 80–90 range bringing the trajectory back toward the Commission baseline.

What to use for which purpose

Best practice for corporate carbon price scenario use:

• Capex decisions: Use a central-case scenario with sensitivities to +/-30% to inform IRR calculations on decarbonisation projects. Decarbonisation IRRs at the central case should be the principal decision criterion; sensitivities check robustness.
• Transition plan disclosure (ESRS E1-1): Use multiple scenarios (typically three) covering the range of policy outcomes, with explicit assumptions documented.
• SBTi target validation: Use the sectoral decarbonisation pathway directly rather than a price-derived pathway; the SBTi framework is sector-specific, not price-derived.
• Treasury hedging: Use the operative forward curve from EEX and ICE December contracts, supplemented by scenario analysis for hedge sizing decisions.

Decision Tree: Is My Activity Covered by ETS1 or ETS2?

For an operator working through whether a specific facility, fleet, or activity is in scope, the following decision sequence captures the principal scope tests as of May 2026.

1. Is the activity an Annex I activity at an installation exceeding the capacity threshold? Combustion >20 MW, refining, coke, iron and steel, primary aluminium, cement clinker, lime, glass, ceramics, pulp, paper, specific chemicals, etc. If yes — ETS1 stationary scope.
2. Is the activity intra-EEA aviation, or departing EEA-to-Switzerland or EEA-to-UK aviation? If yes — ETS1 aviation scope.
3. Is the activity maritime, vessel ≥ 5,000 GT, on a voyage involving an EU port? 100% if intra-EU, 100% in EU ports, 50% if EU-to-non-EU. If yes — ETS1 maritime scope.
4. Are you a fuel supplier placing road-transport, buildings-heating, or small-industry fuels on the EU market? If yes — ETS2 scope (monitoring from 2025, compliance from 2028).
5. None of the above? Activity is not directly in EU ETS scope. May still be downstream-affected: a road-transport-fuel consumer faces ETS2 cost passed through from the fuel supplier; a CBAM-good importer faces CBAM cost passed through to the EU buyer; an indirect-emissions exposure via Scope 2 electricity carries an embedded ETS cost in the retail electricity price.
6. Is the installation in Northern Ireland and is electricity generation? Special case — covered by EU ETS under the Northern Ireland Protocol / Windsor Framework. All other UK-based installations are in the UK ETS, not the EU ETS.
7. Cross-EU/UK operations? Maintain dual compliance for EU and UK separately; watch for the EU–UK linkage outcome to potentially reduce the dual-compliance burden.

Decision Tree: Free Allocation or Full Auctioning?

For an ETS1 operator working out whether the installation receives free allocation, the decision sequence:

1. Is the activity electricity generation (with no Annex I non-power activity at the same installation)? If yes — full auctioning. Electricity generators do not receive free allocation under the Phase 4 architecture (except for transitional free allocation for modernisation in eligible lower-income Member States, which terminates at end-2024 under the 2023 reform).
2. Is the sector on the carbon-leakage list (Commission Delegated Decision (EU) 2019/708 or successor)? If yes — full Carbon Leakage Exposure Factor of 1.0 applies; eligible for free allocation against the product benchmark.
3. Is the sector not on the carbon-leakage list? CLEF declines through Phase 4 and reaches zero by end-Phase 4 for most non-listed sectors. Effective full auctioning.
4. Is the sector a CBAM sector (iron and steel, cement, aluminium, fertilisers, hydrogen)? Free allocation reduces by the CBAM factor schedule from 2026: 2.5% / 5% / 10% / 22.5% / 48.5% / 61% / 73.5% / 86% / 100% — reaching zero free allocation by 2034.
5. From 2026: are you meeting the energy-efficiency / carbon-neutrality plan conditionality? Free allocation in the second allocation period (2026–2030) is conditional on either a recent energy-management audit or implementation of carbon-neutrality plans for the worst-performing installations. Failure to meet conditionality reduces or removes free allocation.
6. Are you a new entrant? The New Entrants Reserve provides allocation to new installations or capacity expansions on application; allocation is calculated against the product benchmark for the relevant activity.

Sector Notes

Power generation

The largest single sector by EUA volume. Full auctioning since 2013 (with limited transitional free allocation for modernisation in lower-income Member States, terminating end-2024). EU power-sector CO₂ emissions fell substantially in 2023 (a 47.6% reduction from 2005 levels by end-2023), driven by coal-to-gas switching, renewable energy buildout (particularly wind and solar), and demand-side moderation. The 2024–2025 EUA price correction was substantially attributable to continued power-sector decarbonisation. See Scope 2 electricity methodology.

Iron and steel

CBAM sector. Free allocation phasing out 2026–2034. Sector-leading operators (ArcelorMittal, Thyssenkrupp, SSAB, Tata Steel) are in active transition from blast-furnace primary steel to direct-reduced iron via hydrogen (HBI/DRI-EAF), with capex programmes typically EUR 1–3 billion per major mill. The Innovation Fund has supported multiple steel decarbonisation projects.

Cement

CBAM sector. Carbon-intensity benchmark of 0.693 tCO₂/t clinker (Phase 4 update). Sector decarbonisation via clinker substitution (calcined clay, ground-granulated blast-furnace slag, fly ash, limestone), alternative fuels (waste-derived, biomass), CCS deployment (Norcem Brevik in Norway, Heidelberg’s Padeswood in Wales, Holcim’s Holcimo CCS projects). Sector pathway under SBTi requires reductions of approximately 20% in clinker intensity by 2030 versus 2020.

Aluminium

CBAM sector for primary and downstream. The aluminium sector has the structural challenge of large process emissions from anode consumption and PFC release that cannot be fully eliminated through renewable-electricity sourcing alone. Inert-anode technology (Elysis, Rio Tinto/Alcoa partnership) is the long-term abatement pathway; in the meantime, increased recycling intensity is the principal sector-level lever.

Chemicals

Mixed coverage: ammonia production, hydrogen production, soda ash, nitric and adipic acid, glyoxal/glyoxylic acid all in ETS scope. Hydrogen production was added to CBAM in 2026 (recognising the strategic importance of low-carbon hydrogen). Sector transition to green hydrogen, electrification of cracking, and biorefinery integration.

Refining

All major EU refineries in scope. Sector is in structural decline as transport-fuel demand shifts to electrification; refinery decarbonisation includes hydrogen-fuelled process heat, electrification of utilities, and CCS where geologically appropriate.

Glass and ceramics

Glass-melting and ceramics-firing in scope. Sector transition includes electrification of furnaces, hydrogen-burner trials, and alternative-raw-material sourcing.

Pulp and paper

In scope where production capacity thresholds met. Sector has relatively low marginal abatement cost compared to other heavy-industry sectors, with biomass-fuelled boilers (recovery boilers in kraft pulp mills) providing a large biomass-emission-zero share.

Aviation

Free allocation fully phased out from 2026. Sector transition includes sustainable aviation fuel deployment (driven by the ReFuelEU Aviation regulation and by the 20-million-allowance SAF reserve), aircraft fleet renewal toward more efficient designs, and air-traffic-management optimisation.

Maritime

In ETS scope since 2024, phasing to 100% surrender by 2027. Sector transition includes alternative fuels (ammonia, methanol, hydrogen), efficiency retrofits, slow-steaming practices, and (long-term) wind-assisted propulsion. The FuelEU Maritime regulation complements the ETS by setting GHG-intensity standards on fuel used by ships calling at EU ports.

Common Misinterpretations

Common Reporting Errors

1. Boundary errors between installation operator and reporting entity. The ETS compliance obligation rests on the installation operator (the entity holding the GHG-emissions permit); the corporate Scope 1 inventory boundary rests on the reporting entity under the chosen consolidation approach (operational control or financial control). Where the two diverge — in joint ventures, lease arrangements, or operating contracts — double-counting or omission errors arise.
2. NCV vs GCV confusion. The MRR uses net calorific value (NCV) for fuel-input calculations, consistent with IPCC inventory practice. Gross calorific value (GCV, also called higher heating value) is approximately 10% higher than NCV for natural gas. A calculation using GCV where NCV is required produces a systematic over-estimate by approximately 10%.
3. Missing flaring and venting emissions. Flared and vented gases at industrial installations are emissions sources that some operators inadvertently omit. The MRR specifically requires flaring and venting to be captured in the Monitoring Plan and the emissions report.
4. Treating biomass as zero-emission without sustainability verification. Under MRR Annex IV, biomass emissions are carried at a factor of zero only where the biomass meets the sustainability and GHG-saving criteria. Without that verification, the biomass emission factor is the relevant carbon-content default value.
5. Confusing process emissions with combustion emissions. In cement and lime production, process emissions from carbonate decomposition are the majority of emissions, not the fuel combustion. Both must be captured, with the appropriate methodology for each.
6. Misapplying the carbon-leakage list to non-listed sub-sectors. The carbon-leakage list operates at the four-digit NACE sub-sector level. Operators sometimes assume the entire NACE Division is on the list because some sub-sectors are; the correct check is at the specific NACE four-digit code that matches the installation’s principal activity.
7. Misapplying free allocation conditionality. From 2026, free allocation is conditional on energy-management audit completion or carbon-neutrality plan implementation. Operators that miss the conditionality deadline lose free allocation for the affected year; remediation does not restore prior-year entitlement.
8. Counting freely-allocated allowances that have been sold as “still available for surrender”. Once an operator transfers freely-allocated EUAs out of its operator-holding account (whether to sell on the market or to transfer to a parent entity), the operator no longer has those EUAs available for surrender. The surrender obligation must then be covered by purchasing EUAs at market price.
9. Missing the 30 September surrender deadline thinking it is still 30 April. The shift from 30 April to 30 September applied from compliance year 2024 onward. Operators on legacy compliance calendars sometimes carry forward the older deadline.
10. Using EUA market price for ESRS E1-9 financial-impact disclosure without proper accounting treatment. EUAs held for surrender are typically accounted as intangible assets under IAS 38 (with the cost-or-revaluation accounting policy choice) or as inventory under IAS 2. The choice substantially affects how unrealised gains and losses flow through the financial statements. An ESRS E1-9 disclosure must reconcile to the underlying accounting treatment.
11. Treating ETS surrender obligations as Scope 3 or Scope 2. ETS surrender is for the operator’s own Scope 1 emissions at owned/operated installations. It is not a Scope 3 indirect emission and is not a Scope 2 purchased-electricity emission. Confusion arises when corporates with low Scope 1 but high purchased-electricity Scope 2 implicitly carry an embedded ETS cost through the electricity price — that is a Scope 2 financial exposure, not a Scope 1 ETS surrender obligation.

Implementation Workflow

For an operator implementing EU ETS compliance from a fresh start — either a new installation, a recently-acquired installation, or an installation transitioning into scope (such as the maritime expansion of 2024 or the ETS2 scope from 2028) — the practical workflow runs as follows.

1. Scope determination (1–2 weeks). Confirm whether the installation, fleet, or activity is in Annex I scope based on activities and capacity thresholds. For borderline cases, consult the national competent authority for an interpretation.
2. Permit application (4–12 weeks). Apply to the national competent authority for the greenhouse-gas-emissions permit. The application includes the description of installation activities, capacity, and the draft Monitoring Plan. Permit issuance is typically 6–12 weeks depending on Member State.
3. Monitoring Plan development (4–8 weeks). Develop the Monitoring Plan per MRR requirements. Specify methodology (calculation-based or measurement-based), tier levels for each parameter, instrumentation, data flow, and personnel responsibilities. Submit for competent authority approval.
4. Instrumentation and data systems (2–6 months). Install required measurement instrumentation (fuel meters, flue-gas analysers, CEMS where applicable). Implement data-capture systems that flow from raw measurement to the MRR-compliant aggregation. Establish quality-assurance procedures.
5. Verifier engagement (1–2 months). Engage an accredited verifier with the correct sectoral accreditation. Verifier reviews the Monitoring Plan, the data systems, and the operator’s quality controls in advance of the first verification.
6. First emission year monitoring. Begin emission monitoring under the approved Monitoring Plan. Capture all required data; maintain documentation; handle any deviations or changes to the Monitoring Plan through the approved-change process with the competent authority.
7. First Annual Emissions Report (by 31 March of year Y+1). Compile the Annual Emissions Report covering year Y emissions, using the verified methodology. Submit to the verifier for verification by approximately mid-March to allow time for any verification findings before the 31 March submission deadline.
8. Free allocation determination (parallel to first emission year). If eligible for free allocation, submit the New Entrants Reserve application (or for existing installations, the National Implementation Measures update) to the competent authority. Receive notification of free allocation entitlement.
9. EUA position management. Build the treasury process for EUA acquisition: auction participation, secondary market purchases, futures hedging book, free-allocation position. Decide the accounting treatment (typically IAS 38 intangible asset or IAS 2 inventory) and the related financial reporting impacts.
10. First surrender (by 30 September of year Y+1). Surrender EUAs equal to verified year Y emissions through the national registry. Receive EUTL confirmation.
11. Annual cycle. Year-on-year: emit, monitor, report (by 31 March), receive free allocation (by 30 April), surrender (by 30 September). Watch for regulatory amendments (Commission Decisions on annual EU-wide quantity, updates to the carbon-leakage list, CBAM coverage expansions, ETS2 launch).

Future Evolution

Three trajectories will shape the EU ETS over the coming decade.

The 2025–2030 implementation curve. The current Phase 4 architecture is operationally settled. The remaining implementation arc is: ETS2 launch in 2028 (postponed from 2027); maritime CH₄/N₂O addition in 2026 and 100% surrender from 2027; CBAM acceleration from 2026 through 2034; potential inclusion of municipal waste incineration from 2028 (subject to Commission review); the EU–UK ETS linkage negotiation outcome; possible Phase 5 design directive aligned with the 2040 90% climate target. Expect heavy enforcement activity around the 2030 free-allocation cliff and around CBAM enforcement infrastructure as the financial obligation ramps up.

The 2040 target and Phase 5 architecture. The European Commission has proposed a 2040 climate target of 90% net GHG emission reduction versus 1990 — under legislative process in 2024–2026 and likely to be adopted before end-2026. Phase 5 of the EU ETS (2031 onward) must be designed against the 2040 target trajectory; the design directive will need to set the Phase 5 LRF, the cap trajectory to 2040, the post-2030 free-allocation regime for non-CBAM sectors, the integration of ETS1 and ETS2 (or their continued separation), and the role of EU ETS in supporting permanent carbon removals (a question currently pending under the EU Carbon Removals Certification Regulation framework). The Phase 5 design directive is expected in 2026–2027.

International carbon-market linkage. The EU ETS is linked with the Swiss ETS since 2020. The EU–UK linkage negotiation began in 2025. Additional bilateral linkages (potentially with South Korea’s K-ETS, China’s national ETS as it matures, or other compliance markets) remain under exploration. Each linkage trades depth (deeper, more liquid carbon markets with more cost-effective abatement) against control (each system surrenders some unilateral policy flexibility). The Article 6.2 cooperative-implementation mechanism under the Paris Agreement is the broader international architecture under which linkages may operate.

Frequently Asked Questions

Sources and References

Every numerical claim and methodological statement in this article reconciles to the primary sources below.

Primary EU instruments

• European Parliament and Council, Directive 2003/87/EC of 13 October 2003 establishing a system for greenhouse gas emission allowance trading within the Community, as amended (consolidated text).
• European Parliament and Council, Directive (EU) 2023/959 of 10 May 2023 amending Directive 2003/87/EC establishing a system for greenhouse gas emission allowance trading within the Union and Decision (EU) 2015/1814 concerning the establishment and operation of a market stability reserve for the Union greenhouse gas emission trading system, OJ L 130, 16 May 2023.
• European Parliament and Council, Regulation (EU) 2023/956 of 10 May 2023 establishing a carbon border adjustment mechanism, OJ L 130, 16 May 2023.
• European Parliament and Council, Regulation (EU) 2023/955 of 10 May 2023 establishing a Social Climate Fund and amending Regulation (EU) 2021/1060, OJ L 130, 16 May 2023.
• European Parliament and Council, Directive (EU) 2018/410 of 14 March 2018 amending Directive 2003/87/EC to enhance cost-effective emission reductions and low-carbon investments, and Decision (EU) 2015/1814.
• European Parliament and Council, Directive 2009/29/EC of 23 April 2009 amending Directive 2003/87/EC so as to improve and extend the greenhouse gas emission allowance trading scheme of the Community.
• European Parliament and Council, Directive 2008/101/EC of 19 November 2008 amending Directive 2003/87/EC so as to include aviation activities in the scheme for greenhouse gas emission allowance trading within the Community.
• European Parliament and Council, Decision (EU) 2015/1814 of 6 October 2015 concerning the establishment and operation of a market stability reserve for the Union greenhouse gas emission trading scheme, as amended.
• European Parliament and Council, Regulation (EU) 2021/1119 (European Climate Law).
• European Parliament and Council, Directive (EU) 2022/2464 (Corporate Sustainability Reporting Directive).
• European Parliament and Council, Regulation (EU) 2015/757 on the monitoring, reporting and verification of carbon dioxide emissions from maritime transport (MRV Maritime Regulation), as amended.

Commission implementing and delegated acts

• European Commission, Commission Decision (EU) 2023/1575 of 27 July 2023 on the Union-wide quantity of allowances to be issued under the EU Emissions Trading System for 2024, OJ L 192, 31 July 2023.
• European Commission, Commission Decision (EU) 2024/1797 of 27 June 2024 amending Decision (EU) 2023/2440, OJ L, 2024/1797, 28 June 2024.
• European Commission, Commission Implementing Regulation (EU) 2018/2066 on the monitoring and reporting of greenhouse gas emissions pursuant to Directive 2003/87/EC (MRR), as amended.
• European Commission, Commission Implementing Regulation (EU) 2018/2067 on the verification of data and on the accreditation of verifiers pursuant to Directive 2003/87/EC (AVR).
• European Commission, Commission Delegated Regulation (EU) 2019/331 determining transitional Union-wide rules for harmonised free allocation of emission allowances, as amended.
• European Commission, Commission Delegated Decision (EU) 2019/708 determining the list of sectors and subsectors deemed at risk of carbon leakage for the period 2021 to 2030.
• European Commission, Commission Regulation (EU) No 1031/2010 (Auctioning Regulation), as amended.
• European Commission, Commission Implementing Regulation (EU) 2025/2620 on the SEFA methodology for CBAM.
• European Commission, Commission Implementing Regulation (EU) 2025/2621 on default values for CBAM embedded emissions.

Commission reports and communications

• European Commission, Carbon Market Report 2025, COM(2025) 735 final, Brussels, 3 December 2025.
• European Commission, Climate Action Progress Report 2024, COM(2024) 498 final.
• European Commission, COM(2022) 150 final — Fit for 55 package, 14 July 2021.
• European Commission, The European Green Deal, COM(2019) 640 final, 11 December 2019.
• European Commission, COM(2025) 990 final — Temporary Decarbonisation Fund proposal, 17 December 2025.

Supervisory and market reports

• European Securities and Markets Authority (ESMA), EU Carbon Markets Report 2025, ESMA50-481369926-30552, 22 October 2025.
• European Securities and Markets Authority (ESMA), EU Carbon Markets Report 2024, ESMA50-43599798-10379, 7 October 2024.
• European Environment Agency, Use of auctioning revenues generated under the EU Emissions Trading System — Indicators.
• International Carbon Action Partnership (ICAP), EU Emissions Trading System (EU ETS) factsheet, May 2026.
• International Carbon Action Partnership (ICAP), EU Emissions Trading System for buildings and road transport (EU ETS 2) factsheet, May 2026.
• European Roundtable on Climate Change and Sustainable Transition, 2025 State of the EU ETS Report, May 2025.

International framework

• United Nations Framework Convention on Climate Change, Kyoto Protocol to the United Nations Framework Convention on Climate Change, adopted 11 December 1997.
• United Nations Framework Convention on Climate Change, Paris Agreement, adopted 12 December 2015.
• International Civil Aviation Organization, Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).

UK instruments and reports

• The Greenhouse Gas Emissions Trading Scheme Order 2020 (UK Statutory Instrument 2020/1265), as amended.
• UK ETS Authority, UK Emissions Trading Scheme: a policy overview, GOV.UK.
• UK ETS Authority, Authority Response to Free Allocation Review, November 2025.
• UK ETS Authority, Response to Future Markets Policy Consultation, 4 December 2025.
• UK ETS Authority, Response to Maritime Scope Expansion Consultation, 26 November 2025.
• HM Treasury and HMRC, UK CBAM Policy Update, 26 November 2025.

Scientific basis

• IPCC, AR6 Working Group I Contribution to the Sixth Assessment Report — Chapter 7 and Table 7.SM.7 (GWP-100 values), 2021.
• IPCC, 2006 IPCC Guidelines for National Greenhouse Gas Inventories.

Adjacent corporate disclosure frameworks

• WRI & WBCSD, The Greenhouse Gas Protocol Corporate Accounting and Reporting Standard.
• European Sustainability Reporting Standards, ESRS E1 (Climate change), EFRAG, 2023.
• Science Based Targets initiative, Corporate Net-Zero Standard.
• International Energy Agency, World Energy Outlook 2025, October 2025.

Verification standards

• ISO/IEC 17029:2019, Conformity assessment — General principles and requirements for validation and verification bodies.
• ISO 14065:2020, General principles and requirements for bodies validating and verifying environmental information.
• European Parliament and Council, Regulation (EC) No 765/2008 setting out the requirements for accreditation and market surveillance.

Related GreenCalculus reference pages

• GHG Protocol Corporate Standard
• GHG Protocol Scope 3 Standard
• GHG Protocol Scope 2 Guidance
• CSRD / ESRS E1
• SBTi Corporate Net-Zero Standard
• ISO 14064-1
• IPCC AR6
• IPCC 2006 Guidelines
• UK DEFRA Emission Factors
• TCFD Recommendations
• RE100 Technical Criteria
• EU F-Gas Regulation 2024
• ISO 14067 Product Carbon Footprint
• ISO 14040 / 14044 LCA
• BS EN 15978 Whole-Life Carbon for Buildings
• GHG Protocol Land Sector and Removals Standard
• Scope 1 emissions
• Scope 2 emissions
• Scope 3 emissions
• CO₂e — carbon dioxide equivalent
• Global warming potential
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Electricity emission factor
• Scope 2 location-based
• Scope 2 market-based
• Scope 2 location-based vs market-based
• IPCC AR6 GWP values
• DEFRA emission factors
• IEA grid emission factors 2026
• Natural gas combustion methodology
• Diesel combustion methodology
• LPG combustion methodology
• Coal combustion methodology
• Scope 2 electricity methodology
• Scope 2 market-based methodology
• SBTi absolute contraction approach
• Scope 1 combustion calculator
• Scope 2 electricity calculator
• SBTi near-term target calculator
• SBTi readiness checklist

What changed in this revision

Updated 11 May 2026. Initial publication. Reflects Directive 2003/87/EC as substantially amended by Directive (EU) 2023/959 (10 May 2023, OJ L 130, 16 May 2023) as the operative legal basis of the EU ETS, the Phase 4 (2021–2030) cap trajectory with Linear Reduction Factor of 4.3% over 2024–2027 and 4.4% from 2028, the 90 million allowance rebasing in 2024 and 27 million allowance rebasing in 2026, the maritime sector inclusion from 1 January 2024 with 40% / 70% / 100% surrender phase-in over 2025–2027 and CH₄/N₂O addition from 2026, the aviation free allocation phase-out completed in 2026, the postponement of ETS2 compliance from 2027 to 2028 by EU Council and Parliament decision in March 2026, the CBAM definitive phase beginning 1 January 2026 with the 2.5% / 5% / 10% / 22.5% / 48.5% / 61% / 73.5% / 86% / 100% phase-out schedule running through 2034, the EUA price series anchored at 2023 annual average EUR 83.66, 2024 annual average EUR 65.00, recovery toward the EUR 80–90 range in 2025 and operative April 2026 prices in the EUR 74–76 range, the cumulative EU ETS auction revenue of EUR 265.7 billion through end-2025, the Innovation Fund and Modernisation Fund operational scale (EUR 2.4 billion and EUR 6.3 billion respectively in 2024), the Social Climate Fund EUR 86.7 billion total over 2026–2032, the 30 September surrender deadline shift from 30 April effective compliance year 2024 onward, the MSR 24% intake rate maintained until 2030 with 3.2 billion allowances invalidated since 2023, the parallel UK ETS regime under SI 2020/1265 with the November 2025 Free Allocation Review response and the GBP 28 Auction Reserve Price from 2026, the EU–UK ETS linkage negotiation initiated 19 May 2025, the UK CBAM scheduled for 1 January 2027, the IPCC AR6 GWP-100 values used in the operative ETS MRR for N₂O and PFC CO₂e conversions, the GHG Protocol Corporate Standard’s classification of ETS-covered emissions as Scope 1 with ETS verification providing Tier 1 data quality, and the CSRD ESRS E1-6 and E1-9 disclosure expectations on ETS verified emissions and EUA price exposure as material financial risk.